1. Field of the Invention
The present invention relates to a television receiver through which a viewer can view a video and program link information and can listen to a sound, and to a method of receiving a broadcast signal.
2. Description of the Related Art
FIG. 10 is a block diagram showing the structure of a conventional television receiver.
With reference to FIG. 10, a television receiver 300 is constituted by a remote control signal receiver 55, a microcomputer 56, a synthesizing processor 60, a sound decoder 90, a program link information decoder 91, a video decoder 92, an AV (Audio Video) input switching unit 93, a tuner controller 94, a display device 95 and a speaker 96.
The microcomputer 56 includes a remote control code analyzer 57, a channel selection controller 58 and a program link information drawing data producer 59.
The sound decoder 90 includes a ground wave sound decoder 90a, a BS (broadcast satellite) sound decoder 90b, a CS (communication satellite) sound decoder 90c and a radio sound decoder 90d. 
The program link information decoder 91 includes a ground wave program link information decoder 91a, a BS program link information decoder 91b and a CS program link information decoder 91c. 
The video decoder 92 includes a ground wave video decoder 92a, a BS video decoder 92b and a CS video decoder 92c. 
The tuner controller 94 includes an AM (amplitude modulation) radio tuner 94a, an FM (frequency modulation) radio tuner 94b, a ground wave tuner 94c, a BS tuner 94d and a CS tuner 95e. 
The tuner controller 94 supplies an instruction for receiving a broadcast signal to any one of the AM radio tuner 94a, the FM radio tuner 94b, the ground wave tuner 94c, the BS tuner 94d and the CS tuner 95e on the basis of a control signal from the channel selection controller 58 which will be described later.
The AM radio tuner 94a receives an AM radio broadcast signal through an antenna 97 to output the received AM radio broadcast signal to a contact SW75 of the AV input switching unit 93. The FM radio tuner 94b receives an FM radio broadcast signal through the antenna 97 to output the received FM radio broadcast signal to a contact SW76 of the AV input switching unit 93. The ground wave tuner 94c receives a ground wave broadcast signal through the antenna 97 to output the received ground wave broadcast signal to a contact SW77 of the AV input switching unit 93. The BS tuner 94d receives a BS broadcast signal through the antenna 97 to output the received BS broadcast signal to a contact 78 of the AV input switching unit 93. The CS tuner 94e receives a CS broadcast signal through the antenna 97 to output the received CS broadcast signal to a contact SW79 of the AV input switching unit 93.
The AV input switching unit 93 switches a switch X to one of the contacts SW75 to SW79 to output any one of the AM radio broadcast signal, the FM radio broadcast signal, the ground wave broadcast signal, the BS broadcast signal and the CS broadcast signal applied from the tuner controller 94 to the sound decoder 90, the program link information decoder 91 and the video decoder 92.
In the sound decoder 90, the ground wave sound decoder 90a decodes the ground wave broadcast signal applied from the AV input switching unit 93 so as to extract a ground wave sound signal and output the same to the speaker 96. The BS sound decoder 90b decodes the BS broadcast signal applied from the AV input switching unit 93 so as to extract a BS sound signal and output the same to the speaker 96.
The CS sound decoder 90c decodes the CS broadcast signal applied from the AV input switching unit 93 so as to extract a CS sound signal and output the same to the speaker 96. The radio sound decoder 90d decodes the AM radio broadcast signal or the FM radio broadcast signal applied from the AV input switching unit 93 so as to extract a radio sound signal and output the same to the speaker 96.
The speaker 96 outputs the sound signal applied from the sound decoder 90 as a sound.
In the program link information decoder 91, the ground wave program link information decoder 91a decodes the ground wave broadcast signal applied from the AV input switching unit 93 so as to extract a ground wave program link information signal and output the same to the program link information drawing data producer 59. The BS program link information decoder 91b decodes the BS broadcast signal applied from the AV input switching unit 93 so as to extract a BS program link information signal and output the same to the program link information drawing data producer 59. The CS program link information decoder 91c decodes the CS broadcast signal applied from the AV input switching unit 93 so as to extract a CS program link information signal and output the same to the program link information drawing data producer 59.
In the video decoder 90, the ground wave video decoder 92a decodes the ground wave broadcast signal applied from the AV input switching unit 93 to extract a ground wave video signal and output the same to the synthesizing processor 60. The BS video decoder 92b decodes the BS broadcast signal applied from the AV input switching unit 93 so as to extract a BS video signal and output the same to the synthesizing processor 60. The CS video decoder 92c decodes the CS broadcast signal applied from the AV input switching unit 93 so as to extract a CS video signal and output the same to the synthesizing processor 60.
A remote controller 400 is employed for transmitting an instruction of each operation such as channel selection, adjustment of videos and sounds and the like as infrared rays.
When a user presses a desired channel selection button out of a plurality of selection buttons, a remote control signal corresponding to the pressed channel selection button is transmitted to the remote control signal receiver 55 of the television receiver 300. The remote control signal receiver 55 receives the remote control signal to apply the same to the microcomputer 56.
In the microcomputer 56, the remote control code analyzer 57 analyzes the remote control signal applied from the remote control signal receiver 55 to output instruction information to the channel selection controller 58. The channel selection controller 58 controls the AV input switching unit 93 on the basis of the instruction information. The program link information drawing data producer 59 produces drawing data of program link information on the basis of the program link information signal applied from the program link information decoder 91.
The synthesizing processor 60 synthesizes the video signal applied from the video decoder 92 and the drawing data of program link information applied from the program link information drawing data producer 59 and displays a synthetic video signal on the display device 95. The display device 95 outputs the applied synthetic video signal as a video.
When a user views a program on the television receiver 300, the user presses the channel of the program that he or she wants to view through the remote controller 400. The remote controller 400 transmits a remote control signal including a channel selection instruction for selecting the pressed channel to the remote control signal receiver 55.
The remote control signal receiver 55 outputs the received remote control signal to the remote control code analyzer 57. The remote control code analyzer 57 analyzes the applied remote control signal to output a channel selection instruction signal to the channel selection controller 58. The channel selection controller 58 controls the AV input switching unit 93 and the tuner controller 94 on the basis of the applied channel selection instruction signal.
In the case of a channel selection instruction signal selecting the channel of a program that is broadcast on a BS 10 channel, for example, the channel selection controller 58 applies a control signal that switches the switch X to the contact SW78 to the AV input switching unit 93. Also, the channel selection controller 58 applies to the tuner controller 94 a control signal that receives a BS broadcast signal of the BS 10 channel from the BS tuner 94d. 
The BS tuner 94d receives the BS broadcast signal of the BS 10 channel through the antenna 97 to output the same to the AV input switching unit 93. The AV input switching unit 93 outputs the BS broadcast signal of the BS 10 channel to the BS sound decoder 90b, the BS program link information decoder 91b and the BS video decoder 92b. 
The BS sound decoder 90b decodes the BS broadcast signal of the BS 10 channel so as to extract a BS sound signal of the BS 10 channel and output the same to the speaker 96. The speaker 96 outputs the BS sound signal of the BS 10 channel as a sound.
The BS program link information decoder 91b decodes the BS broadcast signal of the BS 10 channel so as to extract a BS program link information signal of the BS 10 channel and output the same to the program link information drawing data producer 59. The program link information drawing data producer 59 produces drawing data of program link information on the basis of the applied BS program link information signal of the BS 10 channel to output the same to the synthesizing processor 60. The BS video decoder 92b decodes the BS broadcast signal of the BS 10 channel so as to extract a BS video signal of the BS 10 channel and output the same to the synthesizing processor 60 of the BS 10 channel.
The synthesizing processor 60 synthesizes the BS video signal of the BS 10 channel and the program link information drawing data of the BS 10 channel to output a synthetic video signal of the BS 10 channel to the display device 95. The display device 95 displays the synthetic video signal of the BS 10 channel as a video.
Thus, the user can view the program of the selected BS 10 channel.
In the television receiver 300 shown in FIG. 10, however, a broadcast signal that can be output to the sound decoder 90, the program link information decoder 91 and the video decoder 92 is only the broadcast signal received by any one of the AM radio tuner 94a, the FM radio tuner 94b, the ground wave tuner 94c, the BS tuner 94d and the CS tuner 94e in the tuner controller 94.
Therefore, it is impossible for a viewer to individually select a video, a sound and program link information of the program that he or she wants to view, receive such a video, sound and program link information from different broadcasting stations and view the program in a combination of those individually selected and received video, sound and program link information.
When the viewer is viewing a broadcast program of a baseball match by relay, for example, if it is difficult for him or her to understand a baseball commentator's running commentary, then he or she views a video appeared appearing on a television receiver and simultaneously listens to the sound of a running commentary on the same baseball match received on a radio by minimizing the volume of the sound output from the speaker of the television receiver and by using the radio.
If the viewer views the video appearing on the television receiver and listens to the sound of the running commentary received on the radio at the same time, however, disagreement occurs between the video on the television receiver and the sound from the radio in the case where either a program received on the television receiver or the one received on the radio changes to a CM (commercial) break.
Moreover, if the viewer cannot see a score or positions displayed on a screen well, in the conventional television receiver, it is impossible to view the score or positions by changing the program link information of the baseball match to the one of the same baseball match being broadcast by another broadcasting station and synthesizing the video of the program being viewed at present and the program link information of the program broadcast by another broadcasting station.